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PubMed2000

Color appearance of surfaces viewed through fog.

How do the colors of surfaces seen through fog depend on the chromatic properties of the fog? Prior work (e.g. Chen and D'Zmura, 1998 Perception 27 595-608) shows that the colors of surfaces seen through a transparent filter can be described by a convergence model. The convergence model takes into account color shift and change in contrast. Whether the convergence model can also be applied to fog was tested experimentally with an asymmetric matching task. In computer graphic simulation, observers adjusted the color of a surface seen through fog in order to match the color of a surface seen in the absence of fog. The convergence model fits the data well. The results suggest that the color constancy revealed in this task with fog is described best by a model that takes into account both shift in color and change in contrast.

Color Perception↗

PubMed2002

The perceptual reality of synesthetic colors.

Synesthesia is a remarkable, rare condition where an individual has multimodal perceptual experiences from a unimodal sensory event. We have studied such an individual, an adult male for whom achromatic words and alphanumeric characters are seen in vivid, reliable colors. We used a variety of perceptual tasks to document the perceptual reality of synesthetic colors and to begin to localize the stage of visual processing where this anomalous binding of externally specified form and internally generated color may take place. Synesthetic colors were elicited by forms defined solely by binocular cues or solely by motion cues, which implies a central locus of visual processing for synesthetic binding of form and color. Also included among our measurements was a difficult visual search task on which non-synesthetic subjects required an effortful search through the visual display. Our subject, in contrast to non-synesthetic subjects, accomplished the task with relative ease because the target of the search had a different synesthetic color from the distractors. Thus, synesthetic experiences appear to originate from a binding of color and form that takes place within central stages of visual processing.

Adult↗

PubMed1990

Molecular genetics of X chromosome-linked color vision among populations of African and Japanese ancestry: high frequency of a shortened red pigment gene among Afro-Americans.

Red-green color vision in humans is mediated by the X chromosome-linked highly homologous red and green pigment genes. Color vision defects are caused by deletions and fusions involving these genes. However, we found the frequency of molecular abnormalities among Caucasians to be twice as high as that of phenotypic color vision defects. Among Japanese the frequency of phenotypic and molecular color vision defects was similar (approximately 5%). Among Afro-Americans, molecular defects (largely green-red fusion genes) were at least five times more frequent (21%) than phenotypic color vision defects (approximately 4%). In addition, 35% of Afro-Americans, 2% of Japanese, and less than 1% of Caucasians had a shortened red pigment gene not associated with phenotypic color vision defects. This gene lacked 1.9 kilobases in its first intron and had the identical size as the green pigment gene from which it presumably originated by gene conversion in an ancestral African population. This gene and the closely linked glucose-6-phosphate dehydrogenase A+ variant were in linkage equilibrium. A model for the evolutionary origin of the color vision pigment genes in higher primates is portrayed.

Black People↗

PubMed1993

Using three-color chromosome painting to test chromosome aberration models.

Ionizing radiation induces DNA double-strand breaks (DSB), which interact pairwise to produce chromosome aberrations. There have long been two main competing theories of such pairwise DSB-DSB interactions. The "classical" theory asserts that an unrepaired DSB makes two ends that separate within the cell nucleus, with each end subsequently able to join any similar (nontelomeric) end. The "exchange" theory asserts that at a DSB the chromatin does not separate completely; rather the DSB ends remain associated until repair, or an illegitimate recombination involving another DSB, occurs. The DSB-DSB interaction mechanism was tested by using three-color fluorescence in situ hybridization to paint chromosomes and observe "three-color triplets": three broken and misrejoined chromosomes having cyclically permuted colors. We observed 18 "three-color triplets" in 2000 cells after 2.25 Gy of gamma-irradiation. On the exchange model in its standard form such three-color triplets cannot occur, so this model is inconsistent with the observations. On the classical model, formalized as a discrete time Markov chain embedded at the transitions of a continuous time Markov chain, the frequency of occurrence of three-color triplets can be computed by Monte Carlo simulations. The number of three-color triplets predicted mathematically by the classical model was found to be slightly larger than the observed number. Thus our data, together with our computer simulations, exclude the standard form of the exchange model but are compatible with the classical model. The results are also compatible with other, more complicated models.

Chromosome Aberrations↗

PubMed1990

Ecologically relevant stimuli and color memory.

Ecologically relevant stimuli were developed as an alternative to Munsell color chips. Colored pictures of familiar objects were used to study color memory. We investigated the typicality of color to particular objects. Contextually typical colors were remembered more accurately than atypical colors were. Moreover, this variable had a stronger effect on memory than focality did. We concluded that memory for ecologically relevant material is more impressed by a color's relation to experience than by its intrinsic properties.

Adult↗

PubMed2000

The effect of a nonverbal aid on preschoolers' recall for color.

The purpose of the present study was to investigate whether the provision of a nonverbal memory aid would improve preschoolers' recall of color. Forty 4-year-old children carried out 2 tasks with the same set of colored objects. Colors were not referred to, nor were children told that their recall would later be tested. One day later, the children were split into 2 groups. One group was given a chart containing both the colors of the objects and distractor colors. The other group was not given a chart. Recall for object color was tested. There was an effect of chart provision; children who used the chart recalled more colors correctly than did those who did not use a chart. This result indicates (a) that even very young children can make use of props to facilitate their recall and (b) that such memory aids need not be exact copies of previously seen objects. Implications of these findings for eyewitness recall are discussed.

Child Behavior↗

PubMed2006

Preschoolers' speed of locating a target symbol under different color conditions.

A pressing decision in AAC concerns the organization of aided visual symbols. One recent proposal suggested that basic principles of visual processing may be important determinants of how easily a symbol is found in an array, and that this, in turn will influence more functional outcomes like symbol identification or use. This study examined the role of color on accuracy and speed of symbol location by 16 preschool children without disabilities. Participants searched for a target stimulus in an array of eight stimuli. In the same-color condition, the eight stimuli were all red; in the guided search condition, four of the stimuli were red and four were yellow; in the unique-color condition, all stimuli were unique colors. Accuracy was higher and reaction time was faster when stimuli were unique colors than when they were all one color. Reaction time and accuracy did not differ under the guided search and the color-unique conditions. The implications for AAC are discussed.

Attention↗

PubMed1993

Color as a factor in food choice.

From birth, nature teaches us to make judgements on our environment based in large measure on color. As such, it plays a key role in food choice by influencing taste thresholds, sweetness perception, food preference, pleasantness, and acceptability. Its role is elusive and difficult to quantify, however, which at times has placed color in a secondary role to the other sensory characteristics, a position not entirely consistent with the facts. Color, in a quantitative sense, has been shown to be able to replace sugar and still maintain sweetness perception in flavored foods. It interferes with judgments of flavor intensity and identification and in so doing has been shown to dramatically influence the pleasantness and acceptability of foods. Studies in the literature have used cross-sectional population panels to study these effects, but a recent investigation of color-sensory interactions in beverages has compared the response of a college age group with the response of a panel consisting of a more mature population. Interestingly, the older group showed significant differences from the college age group in their response to the effects of color on several sensory parameters as well as showing a direct correlation between beverage consumption and color. Color is often taken for granted, but this position must be reevaluated in view of such studies and the need to create more appealing foods for different segments of our society.

Carbohydrates↗

PubMed2001

The biotoxicity and color formation results from ozonation of wastewaters containing phenol and aniline.

This study was undertaken to investigate the color forming phenomena and biotoxicity related problems during the initial stage of ozonation in the wastewater containing phenol or aniline. Experimental results indicate that the phenol under alkaline condition and aniline in all pH conditions cause a serious color problem during the period of early initial ozonation. In addition, the ozonated aniline exhibited more severe color formation than the ozonated phenol did. Both of these compounds revealed that either a high compound concentration or low ozone dosage applied incurred a strong color forming phenomena. Moreover, according to the Microtox test, both ozonated byproducts increased the toxicity during early ozonation when the color formation occurred. The EC50-value as COD decreased from 0.72 (for phenol, pH = 7) to 1.38 (for aniline, pH = 4) orders-of-magnitude. This observation implies that the ozonated color formation would generate new toxicity problems if these colored matters were not further oxidized.

Aniline Compounds↗

PubMed2005

Evaluation of experimental designs for two-color cDNA microarrays.

The major goal of two-color cDNA microarray experiments is to measure the relative gene expression level (i.e., relative amount of mRNA) of each gene between samples in studies of gene expression. More specifically, given an N-sample experiment, we need all N(N - 1)/2 relative expression levels of all sample pairs of each gene for identification of the differentially expressed genes and for clustering of gene expression patterns. However, the intensities observed from two-color cDNA microarray experiments do not simply represent the relative gene expression level. They are composed of signal (gene expression level), noise, and other factors. In discussions on the experimental design of two-color cDNA microarray experiments, little attention has been given to the fact that different combinations of test and control samples will produce microarray intensities data with varying intrinsic composition of factors. As a consequence, not all experimental designs for two-color cDNA microarray experiments are able to provide all possible relative gene expression levels. This phenomenon has never been addressed. To obtain all possible relative gene expression levels, a novel method for two-color cDNA microarray experimental design evaluation is necessary that will allow the making of an accurate choice. In this study, we propose a model-based approach to illustrate how the factor composition of microarray intensities changed with different experimental designs in two-color cDNA microarray experiments. By analyzing 12 experimental designs (including 5 general forms), we demonstrate that not all experimental designs are able to provide all possible relative gene expression levels due to the differences in factor composition. Our results indicate that whether an experimental design can provide all possible relative expression levels of all sample pairs for each gene should be the first criterion to be considered in an evaluation of experimental designs for two-color cDNA microarray experiments.

Animals↗

PubMed1999

Color Doppler ultrasonography in patients with subacute thyroiditis.

We studied the utility of color Doppler ultrasonography in patients with subacute thyroiditis. Eighteen patients with subacute thyroiditis (SAT) with painful goiter and thyrotoxicosis underwent color Doppler ultrasonography during the acute and recovery stages of the disease. Thyroid vascularization in these patients was compared with that of 15 untreated patients with Graves' disease and 17 control subjects. During the acute stage of subacute thyroiditis, color Doppler ultrasonography showed low echogenicity without increased tissue vascularity in the affected swollen thyroid. In the recovery stage, color Doppler ultrasonography showed isoechogenicity with slightly increased vascularization. Vascularization became normal at 1 year follow-up time. In contrast, marked by increased vascularization was observed in patients with untreated Graves' disease. Color Doppler ultrasonography showed clear differences between SAT and Graves' disease patients. Vascularity was significantly correlated with serum free thyroxine (FT4) and thyrotropin (TSH) concentrations in the recovery stage (3 months after the initial ultrasonography). Color Doppler ultrasonography accurately visualized lesions without increased vascularity in the acute stage of SAT and lesions of slightly increased vascularity in the recovery stage. Color Doppler ultrasonography may be a useful, noninvasive, and rapid method for differentiating SAT from Graves' disease and for evaluating and monitoring the location and activity of lesions in SAT.

Adult↗

PubMed1985

Older adults' memory for the color of pictures and words.

Young and older adults were presented line drawings or matched words for study that were colored either red, green, yellow, or blue. Half of the research participants were instructed to remember the item and its color (intentional condition), whereas the other half studied only the item (incidental condition). Participants indicated their recognition of items and the color they believed positively recognized items were, regardless of their initial encoding instructions. Data analyses yielded evidence for a decline in color memory in old compared with young adults, particularly with respect to pictures. The color of pictures was generally better remembered than the color of words, particularly in the incidental memory conditions. The discussion suggests the effort required to remember color varies as a function of the stimulus with which it is associated.

Adolescent↗

PubMed2004

Dynamic computed tomography and color Doppler ultrasound of renal parenchymal neoplasms: correlations with histopathological findings.

BACKGROUND: We evaluated whether color Doppler ultrasound (US) had diagnostic accuracy equal to dynamic computed tomography (CT) and whether performing dynamic CT and Doppler US together would be more informative in preoperative diagnosis of renal solid tumors. METHODS: A total of 110 renal solid tumors smaller than 7 cm were evaluated with dynamic CT and Doppler US. We compared the enhancement and the color flow patterns with the histopathological subtypes. RESULTS: Eighty-seven (95.6%) of 91 clear cell carcinomas showed rich enhancement in the cortical nephrographic phase (CNP) and 82 (90.1%) of them had color flow in the Doppler US. Of the total of 110 tumors, nine (8.1%) did not show color flow in spite of rich enhancement in the CNP. Conversely, eight (7.2%) of the 110 tumors showed color flow in spite of poor enhancement, including two chromophobe cell carcinomas and two metastatic renal tumors. CONCLUSIONS: The enhancement pattern in dynamic CT and the color flow pattern in Doppler US were different among the subtypes of RCC. Color Doppler US had diagnostic accuracy equal to dynamic CT in most patients with renal solid tumors. Although Doppler US may play a unique role in the diagnosis of some renal parenchymal solid tumors, it is sufficient to perform dynamic CT alone for diagnosis of clear cell carcinoma.

Adenocarcinoma, Clear Cell↗

PubMed1999

Broiler breast meat color variation, pH, and texture.

Four experiments were conducted to determine the range of breast meat color variation observed in commercial processing plants and its relationship to muscle pH and texture. Boneless, skinless breast fillets were collected weekly from the deboning lines of five commercial processing plants over a 4-wk period. Plant personnel selected breast fillets based on their appearance as being "lighter than normal," "normal," or "darker than normal" in color. Five representative fillets of each appearance classification were transported to a central laboratory for analyses of visual score (1 to 5 with 1 = light, 3 = normal, or 5 = dark), instrumental color, muscle pH, and Allo-Kramer shear (n = 300). Visual scores, lightness (L*), redness (a*), and pH were different (P<0.05) among the three appearance groups, with no significant differences in yellowness (b*). Visual scores averaged 2.4, 3.0, and 3.6, L* was 48.8, 45.6, and 43.1, and pH was 5.63, 5.70, and 5.81 for the lighter, normal, and darker fillets, respectively. There were no significant effects of color group on breast meat texture. Correlations between the color values and pH, however, were all highly significant. These results not only indicate that there are wide variations in breast meat color in commercial production, but they also demonstrate a strong relationship between breast meat color and muscle pH.

Animals↗

PubMed2002

Off-odor volatiles and pink color development in precooked, irradiated turkey breast during frozen storage.

The effect of irradiation on color, lipid oxidation, and volatile production of precooked, irradiated turkey breast during frozen storage was studied. Turkey breast muscles were precooked, aerobically or vacuum-packaged, irradiated at 0, 2.5, or 5.0 kGy using a linear accelerator (electron beam), and then frozen-stored at -40 C. Lipid oxidation, volatiles, color values, gas production, and oxidation-reduction potential (ORP) of meat were determined during 3-mo storage periods. Ionizing radiation produced characteristic off-odor volatiles (dimethyldisulfide and methylthioethane) and lipid oxidation products in precooked, frozen turkey breast. The production of volatiles was accelerated by the confounding effect of high irradiation dose, aerobic packaging, and increased storage time. Volatile production and color changes in irradiated, precooked turkey breast were induced by different mechanisms. Irradiation increased pink color in precooked, vacuum-packaged turkey breast, and the pink color was stable during frozen storage. Decreased ORP and increased CO in irradiated meat indicated that denatured CO-heme pigments could be responsible for the pink color in precooked, irradiated turkey breast. Vacuum packaging was better than aerobic packaging in preventing lipid oxidation and oxidation-dependent volatile production, but pink color in precooked, irradiated turkey breast during frozen storage was maintained.

Animals↗

PubMed2000

Histopathologic diagnosis of superficial soft tissue tumors, related lesions, and simulators: an algorithmic approach based on colors: tumors with predominance of pink.

An algorithmic approach based on colors for histopathologic diagnosis of soft tissue tumors and their simulators is proposed. At scanning magnification, in specimens stained with hematoxylin and eosin, mesenchymal tumors can be classified according to their color. The color of a tumor is basically determined by density, morphology, and distribution of neoplastic cells, and by density and quantity of the stroma. The basic colors that can be observed by neoplasms stained with hematoxylin and eosin are white, pink, red, and blue. Colors may be used as a first step in choosing the algorithm for specific diagnosis of a given mesenchymal neoplasm. Furthermore, colors may be helpful in understanding the histogenesis of a tumor, and this is especially important in soft tissue pathology, because criteria for benignancy and malignancy vary according to the nature of the neoplasm. In this article, tumors with a predominance of pink are analyzed. Pink tumors are composed of cells with abundant eosinophilic cytoplasm and sparse chromatin in their nuclei, such as leiomyoma. In other cases, the pink color in a tumor is determined by abundant fibrous stroma rather than by characteristics of neoplastic cells, such as sclerotic fibroma.

Algorithms↗

PubMed1997

Color quenching in "environmentally friendly" cocktails.

Fluorescent and colored compounds used in molecular biology labs may generate color quench in wipe test samples taken from such labs. The ability of conventional chemical quench curves to correct for color quench caused by fluorescent and colored compounds in "environmentally friendly" cocktails has not been reported. Series of colored samples spiked with 3H or 14C were generated for three fluorescent compounds: ethidium bromide; Hoechst 33342; and fluorescein, and three colored compounds: thiazol yellow G; tartrazine; and a mixture of bromphenol blue and xylene cyanol. Three different "environmentally friendly" cocktails were used: one with a linear alkylbenzene solvent; one with a diisopropylnapthalene solvent; and a third with a phenylxylylethane solvent. The data, generated from two different liquid scintillation spectrometers that use different quench indicating parameters, suggest that the quench from the fluorochromes and colored dyes with moderate amounts of quench can be corrected by chemical quench curves. The data also suggest that the quench curve of diisopropylnapthalene-based cocktails is significantly different from the other "environmentally friendly" cocktails, when examined using tSIE as the quench indicating parameter.

Benzenesulfonates↗

PubMedDate not supplied

Differences in color vision impairment caused by digoxin, digitoxin, or pengitoxin.

Color discrimination ability of 53 patients with congestive heart failure and 32 healthy volunteers treated with digoxin, digitoxin, or pengitoxin was determined with the Farnworth's Munsell 100 hue test. The patients had been treated with digitalis glycosides for several months prior to color vision testing. The volunteers received glycosides until a steady-state plasma concentration was reached. Glycoside plasma levels were measured by radioimmunoassay on the 3 days prior to color vision testing. The total error scores, indices of color discrimination, increased with the glycoside plasma levels. Subjects treated with digitoxin or pengitoxin exhibited no marked elevation in total error score at therapeutic concentrations, whereas 17 of 28 subjects with therapeutic digoxin plasma concentrations (less than 2.0 ng/ml) showed disturbed color discrimination. At toxic plasma levels all 5 digoxin-treated subjects, 7 of 13 digitoxin-treated subjects, and 3 of 8 pengitoxin-treated subjects showed impairment of color discrimination. The greater tendency of digoxin to impair color vision in comparison with digitoxin and pengitoxin may be related to a higher uptake or different distribution in the retina.

Acetyldigoxins↗